POS0283 EFFECT OF CUSTOMISED FOOT ORTHOSES ON PEAK PRESSURE AND PRESSURE TIME INTEGRALS IN CHILDREN WITH JUVENILE IDIOPATHIC ARTHRITIS: A RANDOMISED CLINICAL TRIAL
Authors: A. Fellas, D. Singh-Grewal, J. Chaitow, D. Santos, M. Clapham, A. Coda
Journal: Annals of the Rheumatic Diseases (2023)

<h3>Background</h3> Children with juvenile idiopathic arthritis (JIA) often exhibit joint symptoms in the lower limb. Prolonged joint disease may cause further physical and functional impairment, which can lead to significant disturbances in gait such as abnormal pressure distributions and sub-optimal peak plantar pressures [1-3]. Recent studies have shown that children with JIA compared to an age and sex matched cohort displayed significantly higher peak pressures (PP) in most areas of the plantar foot [2]. Research also showed that children with JIA are displaying elevated pressure time integrals (PTI), meaning they are spending higher amounts of time in the stance phase of gait and less in the swing phase and thus a less propulsive gait [2]. To our knowledge only one previous clinical trial has explored the effect of a mechanical intervention such as foot orthoses (FOs) to improve the distribution of peak plantar pressures in children with JIA [4]. <h3>Objectives</h3> The aim of our randomised clinical trial is to further evaluate the effect of customised prefabricated FOs in improving PTI and PP in children with JIA. <h3>Methods</h3> A multicentre, parallel design, single-blinded randomised clinical trial was used to assess the impact of customised preformed FOs on plantar pressures in children with JIA. Children with a diagnosis of JIA, exhibiting lower limb symptoms and aged 5-18 were eligible. The trial group received a low-density full length, Slimflex Simple device which was customised chair side and the control group received a sham device. PP and PTI were used as the main gait outcomes and were measured using portable Tekscan gait analysis technology at baseline, 3 and 6 months. PP were measured using kilo pascals (kPa) and PTI measured kPa per seconds (kPa/s). Differences at each follow-up were assessed using the Wilcoxon rank sum test. <h3>Results</h3> A total of 66 participants were recruited. Customised prefabricated FOs were effective in altering plantar pressures in children with JIA versus a control device. Reductions of PP in the heel (baseline p=&lt;0.001 (-104.33 kPa), 3-month p=0.004 (-126.16 kPa)), forefoot (baseline p=0.027 (-131.5 kPa)), 5<sup>th</sup> metatarsophalangeal joint (baseline p=0.007 (-37.17 kPa), 3-month p=0.001 (-69.5 kPa), 6-month p=0.016 (-50.91 kPa)) were statistically significant in favour of the trial group. These results were also positively correlated with PTI with the trial group spending less time and pressure on the heel, forefoot and rearfoot than the control. Finally, PP and PTI reductions were also associated with statistically significant increased midfoot contact with the trial device at baseline (29.84 kPa), 3 (24 kPa) and 6-month (43.75 kPa) data collections, showing that the trial intervention was successful in capturing the arch profile of participants and redistributing pressure. The trial intervention was safe and well accepted by participants, which is reflected in the high retention rate (92%). <h3>Conclusion</h3> Clinicians may prescribe customised prefabricated FOs in children with JIA to deflect pressure from painful joints and redistribute from high pressure areas such as the rearfoot and forefoot. <h3>References</h3> [1]Woolnough L, Pomputius A, Vincent HK. Juvenile idiopathic arthritis, gait characteristics and relation to function. Gait &amp; Posture. 2021;85:38-54. [2]Merker J, Hartmann M, Haas J-P, Schwirtz A. Combined three-dimensional gait and plantar pressure analyses detecting significant functional deficits in children with juvenile idiopathic arthritis. Gait &amp; Posture. 2018;66:247-54. [3]Hartmann M, Kreuzpointner F, Haefner R, Michels H, Schwirtz A, Haas J. Effects of juvenile idiopathic arthritis on kinematics and kinetics of the lower extremities call for consequences in physical activities recommendations. International journal of pediatrics. 2010;2010. [4]Coda A, Fowlie PW, Davidson JE, Walsh J, Carline T, Santos D. Foot orthoses in children with juvenile idiopathic arthritis: a randomised controlled trial. Archives of Disease in Childhood. 2014;99(7):649-51. <h3>Acknowledgements:</h3> NIL. <h3>Disclosure of Interests</h3> None declared.